Preheat oven to 350 degrees and line a well greased muffin tin with muffin liners. Begin by prepping the grapefruit. First, zest the peel with a microplane until you have 2 tablespoons of zest. Slice off the top and bottom of the grapefruit.
Stand the grapefruit upright on the cutting board. Starting at the top of the grapefruit, guide your knife down to the base, curving the knife with the shape of the fruit. Continue all the way around the fruit until all of the rind and pith is removed. Use a paring knife to slice along the inside of the membranes, slide out your supremed grapefruit wedges and set aside. Cut grapefruit supremes into fourths measured out to ½ cup.
Finally, juice the grapefruit remains to yield ½ cup of juice.
In a large bowl, whisk together grapefruit juice, grapefruit zest, eggs, honey, coconut oil, almond milk and vanilla. Gently fold in cut grapefruit wedges until just combined.
In a medium bowl, whisk in the dry ingredients: almond flour, coconut flour, salt and baking soda. Add dry ingredients to large bowl of wet ingredients, whisking delicately, yet thoroughly.
Scoop out batter evenly between the 12 muffin tins and bake on the middle rack, for 18-20 minutes until tops are puffed and golden. Let sit at least 15 minutes to firm up before serving. Serve topped with butter and a drizzle of honey.